Mycobacterium tuberculosis Infects Human Visceral White Adipocytes and Expresses Dormancy Genes and Inflammatory Cytokines: The Role of Visceral Adipocytes in Latent Tuberculosis Infection

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This study explores the role of human visceral white adipocytes (hv-WAD) in latent tuberculosis infection (LTBI). While granulomas and macrophages are traditionally viewed as central to TB latency, emerging evidence highlights adipocytes as significant non-canonical host cells that may facilitate bacterial persistence by providing a protective niche. Unlike the immune-driven environment within granulomas, adipocytes can shield Mycobacterium tuberculosis (Mtb) from immune surveillance, promoting survival. In vitro experiments showed that Mtb invades approximately 39% of hv-WAD within 48–72 h post-infection (hpi). Both avirulent H37Ra and virulent H37Rv Mtb strains, when infecting adipocytes, expressed RNA for key virulence factors (19 kDa, 30 kDa, Ag85b, 5KST, CFP10, and ESAT6) and dormancy-associated genes (Icl1, LipY, WhiB3, SodA, and Tgs1) at 72 hpi. Infection stimulated the production of inflammatory cytokines, notably leading to a fivefold increase in TNF-α with H37Rv (p < 0.01). Additionally, we detected Mtb RNA transcripts (IS6110, 5KST, 30 kDa, CFP10, Ag85) in 68% of biopsies from TB asymptomatic patients. The transcripts suggest a metabolically heterogeneous state of mycobacteria. These findings position visceral fat as a potential reservoir for Mtb in latent TB infection and underscore the development of novel diagnostic strategies targeting adipose tissue.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.